CLAPSTONE LEARNING

Why does salt melt ice? Salt lowers the freezing point of water. Ice melts faster when salt is added as the salt lowers the freezing point of the ice, this is known as  freezing point depression . The more salt you add the lower the freezing point. This interesting feature of salt and ice and can be used for lots of fun and easy experiments. Making ice cream with ice and salt Did you know you can make ice cream using milk, salt and ice? This works because as the ice melts heat is absorbed from the surroundings ( the milk mixture ) making them freeze. Did you know you can make your own ice cream in less than 10 minutes with just milk, salt and ice? How to make ice cream with ice and salt Materials A large bag of ice Salt Milk – we used chocolate milk A tablespoon sugar and a tea spoon vanilla essence – options.  Method Pour about a cup of milk into a ziploc bag, add the sugar and vanilla essence ( or just use flavoured milk ). Make sure this bag i...

How to cool a drink quickly Emma Vanstone on July 23, 2014 / 0 comments How can you get a cold drink when you don’t have any in the fridge? Supercool it! How to cool a drink quickly What you need: A metal bowl Water Ice Drink in a glass bottle Salt Method Half fill the bowl with water and ice. Place the bottle in the ice. Add a handful to salt to the water and stir. Watch what happens to the bowl and drink. The salt lowers the melting temperature of the ice, making the water temperature drop  below zero ,  so cooling the drink super fast. We call this supercooling. Extension activities Can you design an experiment as a control condition? Maybe ice and water with no salt?? Can you record the temperature before and after adding the salt? Does the temperature drop further if you add more salt? What happens if you use a plastic bottle? Does it work as well? If you use a smaller drinks container, does it cool faster? Note: If ...

WHY DO LEAVES CHANGE COLOUR? Leaves contain Chlorophyll.   Chlorophyll makes the leaves green and is so dominant that it covers up all the other colours in the leaves.   To figure out what colour a leaf would be without the dominant chlorophyll colour, we can separate the colours by doing this science experiment. This experiment is  very simple  and you likely already have everything you need: MATERIALS: 3 leaves (from the same tree) Rubbing Alcohol Jar Plastic baggie (or plastic wrap) Paper Coffee Filter Small bowl or pan STEPS: 1.  Have your child break the leaves into tiny pieces and put in the jar 2.  pour rubbing alcohol over the leaves until they are just covered 3.  mash and stir the leaves into the rubbing alcohol until the alcohol turns slightly green.  Really give it a good mashing – this is key. 4.  cover the jar with the baggie or plastic wrap and place the jar in a small bowl and pour hot wa...